The present invention relates to a camera, and specifically relates to a camera incorporating a real-image finder, having a structure more compact than ever.
A finder optical system, equipped besides a photographic lens system in a conventional lens shutter camera, etc., can be roughly classified into either a virtual-image finder optical system or a real-image finder optical system. As for the virtual-image finder optical system, however, there has been a problem that it becomes difficult to further minimize the dimensions of the camera, since the diameter of the front lens becomes excessively large when a high magnification capability is introduced into the camera. Therefore, there has been a tendency for a real-image finder optical system to be usually employed for small-sized cameras.
Incidentally, a real-image finder optical system can be further classified into either a type employing a roof mirror or a roof prism, or a type employing a combination of a prism and a flat mirror, a Porro prism or a mirror. A real-image finder optical system, employing a roof mirror or a roof prism, is characterized in that it is possible to position both an objective optical system and an ocular optical system on the same horizontal plane.
However, the following practical problems would tend to occur, when a real-image finder optical system, employing a roof mirror or a roof prism, is installed into a camera. At first, in case that a real-image finder optical system is disposed at such a position where interference with the film and magazine loaded on the camera is avoided, the lowest allowable position for the ocular optical system is determined by default. This fact causes the problem that, when the optical axis of the objective optical system is set on the same horizontal plane as that of the optical axis of the ocular optical system, the positional interval between the photographic lens system and the objective optical system of the finder optical system increases, resulting in enlargement of the parallax, corresponding to the amount of the positional interval.
Further, another problem is that accuracy of the objective optical system should be considerably improved, in order to suppress the total length of the real-image finder optical system, which employs a roof mirror or a roof prism, as shorter as possible.
On the other hand, although the abovementioned problems do not exist in the real-image finder optical system employing a flat mirror or a Porro prism, other problems caused by its structure have occurred. Concretely speaking, the real-image finder optical system of this type is characterized in that the optical axes of the objective optical system and the ocular optical system are shifted relative to each other in the vertical direction of the camera. This characteristic inherently makes the size of the finder unit large in the vertical direction of the camera, resulting in a trend of increased camera body size.
To cope with the abovementioned problem, in one type of conventional cameras, the size of camera body is minimized as compactly as possible by forming a protuberance only at the ocular optical system side of the camera. The camera of this type, however, cannot be shaped in a substantially rectangular parallelepiped, and it has, therefore, been a problem that the camera is inconvenient for storing, and allowances of designing the camera body are increasingly restricted.
Further, an illumination-type information-displaying member, which displays, for instance, the result of a ranging operation, is equipped in a camera to notify the photographer of information in regard to the image-capturing operation. In the above configuration, it is convenient for the photographer to display the information within the visual field of the finder, since the photographer can confirm such information while viewing the finder. It has been a difficult problem, however, to determine a suitable position for disposing the information-displaying member in such a camera, since the real-image finder optical system is a complicatedly shaped structure. Specifically, to display the information within the visual sight of the finder, the information-displaying member should be disposed in the optical path of the real-image finder optical system. For this purpose, a special space should be provided in the periphery of the finder section to arrange the information-displaying member at an appropriate position, resulting in large-sizing trend of the camera body.
To overcome the abovementioned drawbacks in conventional cameras, it is an object of the present invention to provide a camera, which is more compact than ever in spite of having a real-image finder optical system, and make it easier to view the information displayed in the finder.
Accordingly, to overcome the cited shortcomings, the abovementioned object of the present invention can be attained by cameras described as follow.
(1) A camera having a real-image finder, comprising: an objective optical system; an erect-image optical system, having a reflecting surface, to receive a light bundle passed through the objective optical system; and an ocular optical system to receive the light bundle reflected from the reflecting surface of the erect-image optical system; wherein a rear end of the reflecting surface is located at a backward position with respect to a film conveyance surface, and located outside the film conveyance surface, and, a front end of the reflecting surface is located at a forward position with respect to the film conveyance surface, and located inside the film conveyance surface.
(2) The camera of item 1, wherein the reflecting surface is disposed at such a position that the reflecting surface reflects the light bundle, received from the objective optical system, toward a direction of being apart from the film conveyance surface.
(3) A camera having a real-image finder, comprising: an objective optical system; an erect-image optical system, having a reflecting surface, to receive a light bundle passed through the objective optical system; and an ocular optical system to receive the light bundle reflected from the reflecting surface of the erect-image optical system; wherein a part of a film conveyance surface is arranged in a space between the reflecting surface and a body of the camera.
(4) A camera, comprising: a real-image finder including an objective optical system, an ocular optical system and an erect-image optical system; and an information-displaying member for displaying information within a visual field of the real-image finder, wherein, in case that a region, occupied by the objective optical system, the ocular optical system and the erect-image optical system, is projected onto a plane perpendicular to an optical axis of the objective optical system and is surrounded by an imaginary rectangular one side of which is an vertical direction of the camera, at least a part of the information-displaying member is disposed in a region to which neither the objective optical system, the ocular optical system nor the erect-image optical system belongs.
(5) The camera of item 4, wherein the information-displaying member is disposed at a side position of the objective optical system of the real-image finder.
(6) The camera of item 4, wherein the information-displaying member is disposed at a side position of the ocular optical system of the real-image finder.
(7) The camera of item 4, wherein the information-displaying member is disposed at a side position of the objective optical system of the real-image finder, and at a lower position of the ocular optical system of the real-image finder.
(8) The camera of item 4, wherein the information-displaying member includes a light emitting element, and a final reflecting surface of the erect-image optical system is a mirror, and a display-reflecting member, which emits an information-displaying light toward the mirror by reflecting the information-displaying light emitted from the light emitting element of the information-displaying member, is disposed between the mirror and a reflecting surface arranged just before the final reflecting surface.
(9) The camera of item 8, wherein the information-displaying member further includes a masking board.
(10) The camera of item 8, wherein the information-displaying member further includes a connecting board.
(11) The camera of item 3, wherein the reflecting surface is provided so as to reflect the light bundle, received from the objective optical system, in a substantially upward direction.
(12) The camera of item 1, wherein the erect-image optical system includes a Porro prism.
(13) The camera of item 1, wherein the erect-image optical system includes a mirror.
(14) The camera of item 1, wherein the erect-image optical system has a combination of a prism and a mirror.
(15) The camera of item 1, wherein a film reel chamber of a film is disposed at a left side of the camera, viewed from a rear side of the camera.
(16) The camera of item 1, wherein the objective optical system of the real-image finder is disposed at an upper position between a lens barrel and a film reel chamber in the camera.
(17) The camera of item 1, wherein at least a part of the ocular optical system of the real-image finder is disposed at a backward position of a lighting device equipped in the camera.
(18) The camera of item 3, wherein the erect-image optical system includes a Porro prism.
(19) The camera of item 3, wherein the erect-image optical system includes a mirror.
(20) The camera of item 3, wherein the erect-image optical system has a combination of a prism and a mirror.
(21) The camera of item 3, wherein a film reel chamber of a film is disposed at a left side of the camera, viewed from a rear side of the camera.
(22) The camera of item 3, herein the objective optical system of the real-image finder is disposed at a position between a lens barrel and a film reel chamber in the camera.
(23) The camera of item 3, wherein at least a part of the ocular optical system of the real-image finder is disposed at a backward position of a lighting device equipped in the camera.
(24) The camera of item 4, wherein the erect-image optical system includes a Porro prism.
(25) The camera of item 4, wherein the erect-image optical system includes a mirror.
(26) The camera of item 4, wherein the erect-image optical system has a combination of a prism and a mirror.
(27) The camera of item 4, wherein a film reel chamber of a film is disposed at a left side of the camera, viewed from a rear side of the camera.
(28) The camera of item 4, wherein the objective optical system of the real-image finder is disposed at a position between a lens barrel and a film reel chamber in the camera.
(29) The camera of item 4, wherein at least a part of the ocular optical system of the real-image finder is disposed at a backward position of a lighting device equipped in the camera.
Further, to overcome the abovementioned problems, other cameras, embodied in the present invention, will be described as follow:
(30) A camera, characterized in that,
in the camera having a real-image finder, which includes an objective optical system and an ocular optical system, for reflecting the light bundle, passed through the objective optical system, in a substantially upward direction by disposing a first reflecting surface of an erect-image optical system at a backward position of the objective optical system,
a rear end of the first reflecting surface is located at a position more backward than a surface position of a film and a front end of the first reflecting surface is located at a position lower than an upper end of the film.
(31) A camera, characterized in that,
in the camera having a real-image finder, which includes an objective optical system, an ocular optical system and an erect-image optical system, optical axes of which are shifted each other in vertical direction of the camera, and an information-displaying member for displaying information in a visual field of the finder,
the information-displaying member is disposed at such a position that the information-displaying member is included in a range of at least one of a maximum width, a maximum depth and a maximum height of the real-image finder.
(32) A camera, characterized in that,
in the camera, which comprises a real-image finder including an objective optical system, an ocular optical system and an erect-image optical system and an information-displaying member for displaying information within a visual field of the real-image finder,
in case that a region, occupied by the objective optical system, the ocular optical system and the erect-image optical system, is projected onto a plane perpendicular to an optical axis of the objective optical system and is surrounded by an imaginary rectangular one side of which is an vertical direction of the camera, at least a part of the information-displaying member is disposed in a region to which neither the objective optical system, the ocular optical system nor the erect-image optical system belongs.
Since the camera, described in item 30, has a real-image finder, which includes an objective optical system and an ocular optical system, for reflecting the light bundle, passed through the objective optical system, in a substantially upward direction by disposing a first reflecting surface of an erect-image optical system at a backward position of the objective optical system, and a rear end of the first reflecting surface is located at a position more backward than a surface position of a film and a front end of the first reflecting surface is located at a position lower than an upper end of the film, it becomes possible to provide a camera being more compact than ever, and to widen the design flexibility of the camera body, by mounting the real-image finder optical system in an unutilized space, which has been non-available space in conventional cameras. In addition, since the objective optical system of the real-image finder optical system can be disposed near the photographic lens system, it is also possible to suppress the parallax as small as possible.
Since the camera, described in item 31, has a real-image finder, which includes an objective optical system, an ocular optical system and an erect-image optical system, optical axes of which are shifted each other in vertical direction of the camera, and an information-displaying member for displaying information in a visual field of the finder, and since the information-displaying member is disposed at such a position that the information-displaying member is included in a range of at least one of a maximum width, a maximum depth and a maximum height of the real-image finder, it becomes possible to provide a camera more compact than ever by disposing the information-displaying member at an unutilized space created in the body of the camera having the real-image finder optical system of the abovementioned type.
The camera, described in item 32, comprises a real-image finder including an objective optical system, an ocular optical system and an erect-image optical system and an information-displaying member for displaying information within a visual field of the real-image finder. Further, in case that a region, occupied by the objective optical system, the ocular optical system and the erect-image optical system, is projected onto a plane perpendicular to an optical axis of the objective optical system and is surrounded by an imaginary rectangular one side of which is an vertical direction of the camera, at least a part of the information-displaying member is disposed in a region to which neither the objective optical system, the ocular optical system nor the erect-image optical system belongs. Namely, at least a part of the information-displaying member is disposed in a predetermined region of said plane, which is located between upper and lower ends of the projected planes of the three optical systems projected onto said plane, and in which none of the projected planes of the three optical systems exist. Accordingly, it becomes possible to provide a camera more compact than ever by disposing the information-displaying member at an unutilized space created in the body of the camera having the real-image finder optical system of the abovementioned type.
Further, when the information-displaying member is disposed at a side position of the objective optical system of the real-image finder, it becomes possible to effectively utilize the unutilized space formed in a side region of the objective optical system of the real-image finder.
Still further, when the information-displaying member is disposed at a side position of the ocular optical system of the real-image finder, it becomes possible to effectively utilize the unutilized space formed in a side region of the ocular optical system of the real-image finder.
Still further, when the information-displaying member is disposed at a side position of the objective optical system of the real-image finder and at a lower position of the ocular optical system of the real-image finder, it becomes possible to effectively utilize the unutilized space formed in a side region of the objective optical system of the real-image finder and at a lower region of the ocular optical system of the real-image finder.
Still further, when the information-displaying member includes a light emitting element, and a final reflecting surface of the erect-image optical system is a mirror, and a display-reflecting member, which emits an information-displaying light toward the mirror by reflecting the information-displaying light emitted from the light emitting element of the information-displaying member, is disposed between the mirror and a reflecting surface arranged just before the final reflecting surface, the photographer can view the information-displaying image precisely focused on the screen of the finder.
Still further, it is desirable that the information displaying member also includes a masking board and/or a connecting board.
Still further, when a light bundle, passed through the objective optical system of the real-image finder, is reflected in a substantially upward direction by the first reflecting surface of the elect-image optical system disposed at backward position of the objective optical system, it becomes possible to dispose the objective optical system at a position near the photographic lens system, and it is also possible to suppress the parallax as small as possible.
Still further, it is desirable that the elect-image optical system includes a Porro prism and/or a mirror, and more desirable that the elect-image optical system includes a combination of a Porro prism and a mirror.
Still further, when the camera is a reverse loading type, so to speak, in which film reel chamber 12 of the film is disposed at the left side when viewed from the rear side of the camera, it is possible to dispose the real-image finder optical system at a lower position, compared to the case that the driving section is disposed at an upward position of the camera.
Still further, when the objective optical system of the real-image finder is disposed at an upper position between a lens barrel and a film reel chamber in the camera, it becomes possible to effectively utilize, for instance, a triangle dead space formed at the upper space of the lens barrel and the film reel chamber.
Still further, when at least a part of the ocular optical system of the real-image finder is disposed at a backward position of a lighting device equipped in the camera, it becomes possible to effectively utilize an unutilized space formed at the backward space of the lighting device, and it is also possible to dispose the ocular optical system at such a position that the photographer can easily view the finder.